1. Field of the Invention
The present invention relates to a portrait drawing apparatus and, more particularly, to a portrait drawing apparatus allowing novices to draw portraits easily and as desired.
2. Description of the Related Art
One of the common ways to draw portraits is by making use of a certain kind of data processing apparatus known as the portrait drawing apparatus. The portrait drawing apparatus comprises a display unit including a CRT or the like, an input unit through which to enter data, and various controllers. The display unit has on its screen a facial part display area and a portrait drawing area. The facial part display area displays such facial parts as the eyes, nose, mouth, eyebrows, ears, hair, facial contour, mustache, wrinkles and sideburns with which to construct a likeness. The portrait drawing area is an area in which the operator draws a portrait using the facial parts shown in the facial part display area.
To draw a portrait, the operator selects one of the candidates of each facial part displayed in the facial part display area, the selected part best representing the characteristic of the model's facial part in question. The selected facial parts are positioned successively where appropriate in the portrait drawing area until the portrait is completed.
How a portrait is drawn using a conventional portrait drawing apparatus will now be described with reference to the flowchart of FIG. 4. As indicated in FIG. 4, the operator first selects the facial part to be drawn (step F1). With the facial part selected, a collection of candidates of that part is displayed in the facial part display area (step F2). Suppose that the facial part "nose" is selected. The operator then selects the candidate that best represents the characteristic of the model's nose. When the most appropriate facial part candidate is selected, that part is positioned automatically where appropriate in the portrait drawing area (step F3). Automatic positioning of facial parts is implemented both to facilitate the drawing work and to take advantage of the fact that each facial part has its approximately fixed position in the human face (e.g., nose is at the center of the face).
With the nose selected and positioned, a check is made to see if there remain other facial parts to be selected (step F4). In this case, other facial parts need to be selected and positioned and thus step F1 is reached again. In step F1, candidates of the next facial part "eyes" are displayed and examined for selection. In like manner, the other facial parts (mouth, eyebrows, etc.) are selected and positioned. When all facial parts have been dealt with (YES in step F4), the portrait is completed.
One disadvantage of the conventional portrait drawing apparatus is this: it is quite difficult to fully grasp the model's physical features in advance and to select accordingly the best-fit facial parts from among the previously stored facial part candidates. It requires the operator to have experience and artistic tastes.
Another disadvantage of the prior art portrait drawing apparatus is that it lacks flexibility. The apparatus is noted for its ability to allow novices to draw portraits of acceptable quality, letting them select desired facial parts that are positioned automatically into a likeness. However, the prior art portrait drawing apparatus is incapable of accommodating specific requests such as one calling for dislodging a certain facial part a little in a given direction, despite the fact that doing so would improve the quality of the portrait appreciably.
If individual facial parts are allowed to be positioned where desired by the operator, the flexibility of the portrait drawing apparatus increases but the operator has difficulty determining the exact facial part positions. Positioning the facial parts where appropriate is especially difficult for operators unskilled in drawing portraits.